Herring announced last week that he felt the state's ban on gay marriage violates the 14th Amendment. He said that the his office would not defend the law, and would further join the side of the plaintiffs.

Marshall said Herring's move was reminiscent of the 1857 decision, in which the Supreme Court concluded that free or enslaved blacks could not be American citizens and as such did not have standing to sue in federal court.

"Herring has put all of us in the position of Dred Scott, who had no right to counsel in federal court," Marshall said. "An attorney general has a duty to support those laws that are constitutional, and an attorney general has just as strong an obligation and duty not [sic] defend laws that he has concluded are unconstitutional after a careful and thorough review. It's that simple."

Marshall added that Herring should have appointed another counsel to defend the state ban.

"He should have appointed another counsel. But switching sides on this? He took a political position. That’s perfectly fine for him to do that, even though that’s a total flip flop. But he should have appointed somebody else," he said.